In the case of a web-fed rotary press, the register-true coordination of a printing cylinder which prints on one side of a web takes place by means of register regulators. A register deviation which is picked up by a sensor, this being assigned to one web side, is supplied to one input of the register regulator. The register regulator is connected to a bus of a supervisory controller via a further input. The supervisory controller comprises a control station, section computers and service interfaces. The desired values for drive regulation of motors are specified by means of the supervisory controller. The unexamined German patent application DE 197 23 059 A1 indicates in particular that it is important that a color register does not deviate from a tolerance range. The speed of the color register regulation is particularly significant. The faster the register regulation, the more advantageous this is. In order to minimize error delays, it is proposed that a sensor be arranged immediately behind each printing position.
For the purpose of the register regulation, register marks are additionally printed on the web by printing cylinders, for example, and are picked up by means of a pair of sensors that are arranged behind the last print unit. The register marks that are printed on the web are picked up by the sensor and analyzed in a measuring head of the sensor. The ascertained register deviations of the printing cylinders are routed from an output of the sensor to a supervisory controller/regulator.